Allen-bradley Company, LLC

Barry E Sammons

Odo J Struger

Ronald Edwin Schultz

A cluster of control processors are interconnected by a local area network and exchange data to carry out their control functions. Each controller executes a control program containing both conventional instructions and T-instructions which call for an operation on data maintained by another controller in the cluster. All data required to execute T-instructions is stored in a virtual I/O image table and each controller is responsible for keeping its section of this table up-to-date by periodically broadcasting its data on the local area network.

Distributed processing in a cluster of industrial controls linked by a

A programmable controller has input and output multiplexer modules through which I/O data may be transferred. A multiplexer array is stored in the controller memory for storing this I/O data and conventional programmable controller instructions in the user control program may be employed to examine or set specified bits in the stored array. The multiplexer module may take the form of two separate modules in which one module generates a select code to a matrix of switches or operating devices and the other module transfers data to or from a selected row in the matrix.

Multiplexed data handler for programmable controller

A programmable controller includes a microprocessor which operates in response to machine instructions stored in a read-only memory. A control program comprised of programmable controller-type instructions is stored in a random access memory. These are executed by translating their operation codes into the starting addresses of corresponding sets of machine instructions. In addition, one or more 'universal instructions' may be contained in the control program, and when these are read from the random-access memory, they are translated to enable the microprocessor to execute a user defined set of microprocessor machine instructions. These user defined machine instructions may be stored in a read-only memory or they may be stored in the random access memory with the control program. The programmable controller may thus effectively be programmed in two languages, a programmable controller language and a microprocessor machine language.

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Whitefish Bay, WI, United States of America

Barry E Sammons